Hi Jefferey … You are much nicer than me, but excellent slap down nonetheless!!! I had a couple of “Honest” professional comments about your very interesting photo above. Do you own that stone? There are a lot of people out there that would swear your specimen was a rough diamond as we have seen above and in my daily practice in Las Vegas. I have to admit that I have never come across a quartz like your photo with such defined Trigons. Let me know where I can get such a specimen! It has great teaching potential about it. Since this a teaching forum, I would like to post a couple of photos for comparison for our respectful members. I gave some more thought to the other possible singly refractive stones out there that have been mistaken as rough diamonds and brought to my lab in Las Vegas!! Fluorite, it is cubic and forms in octahedrons (usually devoid of trigons though) and is singly refractive. Grossularite Garnets … singly refractive and near to completely colorless … photo from Bill Wise attached. The Trigons in your quartz are much different that those on a diamond octrahedron. The alignment of the Trigons is very specific to the diamond’s internal crystal structure. The points of the Trigons almost always point directly to a rib of the octahedron and are parallel to the 3 point plane. Photo of rough diamond octahedron attached for comparison for our members. Enjoy! Michael in Las Vegas at The Diamond Grader Lab. 
